The benefits of stretching and strengthening muscles, particularly in sports, are well known. In baseball, for example, batters routinely swing a bat with added weight while on deck awaiting their turn at bat. Pitchers stretch and warm up by throwing many balls prior to facing the batters. Runners and swimmers likewise warm up with various stretching exercises before competing, as do football and basketball players.
Players in golf also benefit from stretching and warming up before play. In addition to a player's strength, flexibility may also affect his or her ability to drive a golf ball far. One theory is that the bigger the shoulder turns during the swing motion, the farther the player can drive the ball. Another theory holds that the longest hitters do not necessarily have the biggest shoulder turns, but rather have the widest gap, called the X-Factor, between the turning of the hips and shoulders at the top of the swing. Under this theory, the wider the gap, the farther the player can hit the ball.
A more recent theory holds that the X-Factor is not as important as the X-Factor Stretch—the gap between the hips and shoulders as the club starts down toward the ball. See P. Cheetham, P. Martin, R. Mottram, B. St. Laurent, Second Prize: The X-Factor Stretch, Golf Magazine, March 2001, at 98. At the beginning of the downswing, the hips start rotating before the shoulders finish turning back. Furthermore, the hips rotate faster than the shoulders, increasing the hip-shoulder separation during the early part of the downswing. Increasing this gap is believed to increase the club head speed and add power to the swing for hitting the ball farther.
There is currently known in the prior art a wide variety of training devices for improving a player's swing. Such devices typically improve the swing by teaching the proper swing mechanics. Such devices, however, do not adequately address a player's flexibility and range of motion, particularly in view of the above theories. Thus, significant improvements to a player's swing, and in particular the ability to drive a golf ball far, are believed possible with better means for improving a player's flexibility and range of motion. Improvements in other sports as well are believed possible with better means for improving a player's flexibility and range of motion. Moreover, in any sport, stretching and increased flexibility are believed to improve performance and lessen the likelihood of injury.